Arc reducing electric switch



April 25, 1933. T. E. MCDOWELL 1,905,038

ARC REDUCING ELECTRIC SWITCH v Filed Aug. 15, 1930 2 Sheets-Sheet l All/U J/iflg A8 1%]! I INVE'NTOR 7%ZAM ATTORNEYS April 25, 1933. T. E. M DOWELL 1,905,038

ARC REDUCING ELECTRIC SWITCH Filed Aug. 15, 1930 2 Sheets-Sheet 2 INVENTOR 2%0 5 Z. Jfcflowell ATTORNEYS.

blade.

Patented Apr. 25, 1933 warren- STATES PATENT OFFICE mom E. IcDOW'EI-L, OI CHICAGO, ILLINOIS, ASSIGNOB TO THE FILE-NATIONAL COI- rm, CHICAGO, ILLINOIS, A CORPORATION OF NEW mass! ABC REDUCING ELECTRIC SWITCH Application filed Au ust 15, mo. Serial no. 475,441.

My invention relates to improvements in are reducingelectric switches and the like.

Itha's for one object to provide in combination with an electric switch preferabl of 8 the knifeswitch type, means for bre ingor arresting the arc which is formed when the circuit is broken by the opening of the switch. Other Objects will appear from time to time throughout the specification and claims.

My invention is illustrated more or less diagrammatically in the accompanying drawings, where1n-- Figure 1 is. a plan view- Fi'gure 2 is a section al ofF1gure1; v a

Figure 3 is an elevation of the arc arrestmechanism; 1

igure 4 is a section along the line 4-4 so of Figure 3,; y I

Figure '5 is a section along the line 5--5 of Figure 3; I

Figure 6 is a perspective view of the arc I blade.

A-is a -switch housing comprising a bottom side walls and slotted flanges A whereb the switch housing may be bolted, in place. 1' is a cover for the switch. A is an insulating plate contained within the hous- 80 ing and supported on bosses A and having terminals A A associated with conductor cables A A 'which pass out through suitable apertures in the walls of the housin As shown there are three of these terminals 85 and three cables at each side though there ht be more or less.

, ising upwardly from the insulating plate A are a plurality of pivot brackets B, one

associated with every one of the conductors Pivoted in these brackets are knife switch blades B which blades may be moved into and out of contact with sprin fingers B, there being? pair of fingers or every Exten g across the upper edges of all three of these blades is an insulating bar B which is mounted on the blades so that movement of the bar moves all blades simultaneously. Projecting upwardly from the bar are a plurality of lugs B. Links B 59 pivoted on these lugs are also pivoted on a ong the line 2-2 The plates 0 are rovidedwith tongues switch arm B. This switch arm has offset ends at B which ends are pivoted at B B" inthe wall of the housing, one of the ends B" being outwardly bent and terminating in a switc 1 whereby the switch may be opened or cl B is a switch locking arm associated with a coil spring 'B" and an abutment B" whereby the switch is yieldingly held in open or: closed position as the case may be. All this arrangement is common, conventional switch arrangement. I

Associated with every pair of spring fingers is an arc arresting device. Iteomprises a housing or bracket 0 of porcelain or other suitable materialmounted on the insulating plate A and has spaced side walls and an end member. The spaced side walls invide a slot in the housing through w ich the blade passes. This housing is provided 79 with an ear 0 a ertured to be engaged by the bolt C to ho d it in place on the plate A. A housing encloses a tpeair of spring fingers B. and its end mem r is centrally a rtured as indicated at C to rovide a s ot therein so that the knife b ade may pass through it into and out of engagement with the spring fingers. Toward its upper end above the-ends of the spring fingers, the 7 housing is provided with a plurality of parallel generally horizontal recesses 0 forming ets; in which are loosely socketed choke plates C disposed one plate to a pocket, these choke plates being centrall slotted or notched at C so that the kni blade may pass throu h the notches or slots. The plates are provi' ed with shoulders C for positioning the plates in the housing;

at the forward en which normally are in alignment with the adjacent-side edges of the plates. When the plates areinserted in the recesses or pockets C, the plates are inserted from the back of the housing, that is, from the ri ht-hand side of the housing as viewed in 1 e 4. When the lates have been so inserted, the tongues are'then bent outwardly to engage against the sides of the housing adjacent the pockets for securing the plates in position, as clearly seen handle B outside the housing 68.-

ose

' another or with anything in Figure 5. This manner of securing the plates in position is simple and one which 1s economical in carrying into efiect. The plates C, in this case there being three of them, are separately mounted in the housing G and have no electric contact with one else. The plates C lie in the path of the knife blade as it moves away from the spring fingers in. the direction it travels to break the circuit and the knife blade travels through the slots in such plates C without contacting the plate. The effect of this arrangement is that as the knife blade travels out to break the circuit, the resence alongside of the path of travel 0? the blade of these separate separately insulated, separately mounted choke plates is sufiicient to cause any are which may be drawn out to be choked out or damped out or broken off and their presence prevents the drawing out of an are at the switch points.

I claim:

1. Switch mechanism includin in combination, a contact member, a bla e movable into and out of engagement with said contact membeig an arc queueing device about said contact member, said device comprising a housing having spaced side walls providin a slot, the inner faces of said side walls bein provided with a plurality of spaced para lel grooves forming pockets, metal plates in said grooves disposed one plate to a pocket, said plates having notches therein which are in register with one another and with the housing slot when said plates are in position, the blade member being movable through the registerin notches of said plates and the housing s ot, said plates having pro'ections thereon engaging with the si e wa s to prevent displacement of said plates from said housing.

2. Switch mechanism includin in combination, a contact member, a b ade movable into and out of engagement with said contact member, an arc quenchin device about said contact member, said device comprising a housing having spaced side walls providin a slot, the inner faces of said side we. beinlg 1provided with a plurality of s aced para e grooves forming pockets, notc ed metal plates in said grooves dis posed one plate to a pocket and disposed with the notches in register, a cross member connecting the ends of said walls and having a notch therein in register with the late notches and the housing slot, and the lade member being movable through the registering notches and the housing slot.

3. Switch mechanism including in combis nation, a contact member, a blade movable into and out of engagement with said contact member, an arc quenching device about said contact member, said device comprising a housing having spaced side walls providing a slot, the inner faces of said side walls bem provided with a plurality of spaced para el grooves forming pockets, notched metal plates in said ooves disposed one plate to a pocket an arranged with the notches in register, said blade member bein movable throu h the registering notches 0 said plates an the housing slot, and said plates having shoulders thereon for positionin said plates in said side walls.

4. S witch mechanism including in combination, a contact member, a blade movable into and out of engagement with said con-.

tact member, an arc quenching device about said contact member, said device comprising a housing having spaced side walls providing a slot, the inner faces of said side walls being provided with a ,pluralit of spaced parallel grooves forming poc ets, notched metal plates in said grooves disposed one plate to a pocket and arranged with the notches in register, said blade member being movable through the registering notches of said plates and-the housing slot, and said plates having shoulders thereon for positioning said plates in said side walls, said plates also having tongues thereon bendable against the side walls to lock the plates in position in said side walls.

5. A housing for are quenching purposes comprising a member having a bottom and a top and spaced side walls providing a slot through said housing, the top being notched, said housing being 0 en at its rear, the inner faces of the side we being provided with spaced parallel grooves forming pockets for receiving plates, notched plates in said pockets arranged one late to a pocket and-with the notches in re ster with one anotherand with the slot in e end member of the housing, said plates having shoulders and lu for positionin the plates in the side we the shoulders earin a ainst rear edges of the side walls and t e ugs being bendable against the opposite edges of the side walls for locking t e plates in said housin Signed at Ghica 0, county of C00 and State of Illinois, t is 13th day of August, 1930.

THOMAS E. MoDOWELL. 

